A nickel-hydrogen secondary battery has a positive electrode including a positive electrode mixture which contains a nickel compound as a major component and which is supported on a collector sheet, a negative electrode including a negative electrode mixture which contains a hydrogen absorbing alloy as a major component, a binder and an electrically conductive material and which is supported on a collector sheet, the positive and negative electrodes being stacked up alternately or rolled up with a separator interposed therebetween to form an electrode group, and a battery case containing the electrode group together with an electrolyte, the battery case having an opening closed with a sealing plate which is provided with a positive electrode terminal, wherein the binder contains at least carboxylated styrene-butadiene copolymer latex, the conductive material contains metal flakes or short metal fibers, and an edge portion of the collector sheet of the negative electrode is electrically connected to the battery case via a collector plate welded to the edge portion of the collector sheet.